[readthenotes1]

It would have been better if the requirements also included the domain name had to start with a letter between I and N (inclusive).

But I guess this is what you get when these things get away from technologists.

[jfengel]

Ah, a Fortran joke. That's not just "technologists". That's old farts.

(In Fortran 66, variables didn't have to be declared. They would be integer if they began with I, J, K, L, M, or N. Otherwise it would be floating point [REAL, in Fortran parlance]. To this day it's why for loops usually use "i". With the bonus joke that God is real unless declared integer.)

[mkl]

Maths is the reason for loops use i. Fortran defines variables starting with those letters to be integers because maths has used those letters for iteration, counting, indexing, etc. for centuries. It was natural for a formula translating system to follow suit.

[spauldo]

I think that's still the case, even in the latest FORTRAN standard. It's usually considered good practice to turn it off with IMPLICIT NONE.